Problem: Simplify the following expression: ${-2(4n-6)-9(-2+n)}$
Answer: Distribute the ${-2}$ into the first set of parentheses: $ {-2(}\gray{4n-6}{)} - 9(-2+n) $ $ {-8n+12} - 9(-2+n) $ Distribute the ${-9}$ into the parentheses: $ -8n+12 {-9(}\gray{-2+n}{)} $ $ -8n+12 + {18-9n} $ Rewrite the expression to group the ${n}$ terms and numeric terms: $ {-8n - 9n} + {12 + 18}$ Combine the ${n}$ terms: $ {-17n} + {12 + 18}$ Combine the numeric terms: $ {-17n} + {30}$ The simplified expression is $-17n+30$